Originally Posted by wikipedia
The scramble for the earliest Human
In the 1990s several teams of paleoanthropologists were working throughout Africa looking for evidence of the earliest divergence of the Hominin lineage from the great apes. In 1994 Meave Leakey discovered Australopithecus anamensis, but the find was overshadowed by the news of Tim White's discovery of Ardipithecus ramidus, which pushed back the fossil record to 4.2 million years ago. In 2000 Martin Pickford and Brigitte Senut discovered a 6 million years old bipedal hominin in the Tugen Hills of Kenya, which they named Orrorin tugenensis. And in 2001 a team lead by Michel Brunet discovered the skull of Sahelanthropus tchadensis which was dated as 7.2 million years ago, and which Brunet argued was a bipedal, and therefore a hominin.